Adsorption of nitrogen and water vapor by alluvial soils

We report on the results of investigations on the adsorption of nitrogen at 79 K and water vapor at 293 K on several Polish alluvial soils. The experimental adsorption data have been used to evaluate the surface fractal dimension from Frenkel-Halsey-Hill (FHH) equation and to evaluate the adsorption energy distribution function by using a modified numerical method that has been developed by Stanley and Guiochon [J. Phys. Chem. 97 (1993) 8098-8102] for non-fractal adsorbents. We have investigated the correlations between the surface fractal dimensions and the average values of the adsorption energy with several physico-chemical properties of soils. We have found that these quantities correlate with the content of the clay fraction and with the cation exchange capacity. We did not find any correlation between the geometric or energetic heterogeneity parameters and the content of the organic matter. (C) 2002 Elsevier Science B.V. All rights reserved.